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Diffstat (limited to 'arch/i386/kernel/cpu/cpufreq/speedstep-ich.c')
-rw-r--r--arch/i386/kernel/cpu/cpufreq/speedstep-ich.c424
1 files changed, 424 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-ich.c b/arch/i386/kernel/cpu/cpufreq/speedstep-ich.c
new file mode 100644
index 00000000000..5b7d18a06af
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+++ b/arch/i386/kernel/cpu/cpufreq/speedstep-ich.c
@@ -0,0 +1,424 @@
+/*
+ * (C) 2001 Dave Jones, Arjan van de ven.
+ * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
+ *
+ * Licensed under the terms of the GNU GPL License version 2.
+ * Based upon reverse engineered information, and on Intel documentation
+ * for chipsets ICH2-M and ICH3-M.
+ *
+ * Many thanks to Ducrot Bruno for finding and fixing the last
+ * "missing link" for ICH2-M/ICH3-M support, and to Thomas Winkler
+ * for extensive testing.
+ *
+ * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
+ */
+
+
+/*********************************************************************
+ * SPEEDSTEP - DEFINITIONS *
+ *********************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+
+#include "speedstep-lib.h"
+
+
+/* speedstep_chipset:
+ * It is necessary to know which chipset is used. As accesses to
+ * this device occur at various places in this module, we need a
+ * static struct pci_dev * pointing to that device.
+ */
+static struct pci_dev *speedstep_chipset_dev;
+
+
+/* speedstep_processor
+ */
+static unsigned int speedstep_processor = 0;
+
+
+/*
+ * There are only two frequency states for each processor. Values
+ * are in kHz for the time being.
+ */
+static struct cpufreq_frequency_table speedstep_freqs[] = {
+ {SPEEDSTEP_HIGH, 0},
+ {SPEEDSTEP_LOW, 0},
+ {0, CPUFREQ_TABLE_END},
+};
+
+
+#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "speedstep-ich", msg)
+
+
+/**
+ * speedstep_set_state - set the SpeedStep state
+ * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
+ *
+ * Tries to change the SpeedStep state.
+ */
+static void speedstep_set_state (unsigned int state)
+{
+ u32 pmbase;
+ u8 pm2_blk;
+ u8 value;
+ unsigned long flags;
+
+ if (!speedstep_chipset_dev || (state > 0x1))
+ return;
+
+ /* get PMBASE */
+ pci_read_config_dword(speedstep_chipset_dev, 0x40, &pmbase);
+ if (!(pmbase & 0x01)) {
+ printk(KERN_ERR "speedstep-ich: could not find speedstep register\n");
+ return;
+ }
+
+ pmbase &= 0xFFFFFFFE;
+ if (!pmbase) {
+ printk(KERN_ERR "speedstep-ich: could not find speedstep register\n");
+ return;
+ }
+
+ /* Disable IRQs */
+ local_irq_save(flags);
+
+ /* read state */
+ value = inb(pmbase + 0x50);
+
+ dprintk("read at pmbase 0x%x + 0x50 returned 0x%x\n", pmbase, value);
+
+ /* write new state */
+ value &= 0xFE;
+ value |= state;
+
+ dprintk("writing 0x%x to pmbase 0x%x + 0x50\n", value, pmbase);
+
+ /* Disable bus master arbitration */
+ pm2_blk = inb(pmbase + 0x20);
+ pm2_blk |= 0x01;
+ outb(pm2_blk, (pmbase + 0x20));
+
+ /* Actual transition */
+ outb(value, (pmbase + 0x50));
+
+ /* Restore bus master arbitration */
+ pm2_blk &= 0xfe;
+ outb(pm2_blk, (pmbase + 0x20));
+
+ /* check if transition was successful */
+ value = inb(pmbase + 0x50);
+
+ /* Enable IRQs */
+ local_irq_restore(flags);
+
+ dprintk("read at pmbase 0x%x + 0x50 returned 0x%x\n", pmbase, value);
+
+ if (state == (value & 0x1)) {
+ dprintk("change to %u MHz succeeded\n", (speedstep_get_processor_frequency(speedstep_processor) / 1000));
+ } else {
+ printk (KERN_ERR "cpufreq: change failed - I/O error\n");
+ }
+
+ return;
+}
+
+
+/**
+ * speedstep_activate - activate SpeedStep control in the chipset
+ *
+ * Tries to activate the SpeedStep status and control registers.
+ * Returns -EINVAL on an unsupported chipset, and zero on success.
+ */
+static int speedstep_activate (void)
+{
+ u16 value = 0;
+
+ if (!speedstep_chipset_dev)
+ return -EINVAL;
+
+ pci_read_config_word(speedstep_chipset_dev, 0x00A0, &value);
+ if (!(value & 0x08)) {
+ value |= 0x08;
+ dprintk("activating SpeedStep (TM) registers\n");
+ pci_write_config_word(speedstep_chipset_dev, 0x00A0, value);
+ }
+
+ return 0;
+}
+
+
+/**
+ * speedstep_detect_chipset - detect the Southbridge which contains SpeedStep logic
+ *
+ * Detects ICH2-M, ICH3-M and ICH4-M so far. The pci_dev points to
+ * the LPC bridge / PM module which contains all power-management
+ * functions. Returns the SPEEDSTEP_CHIPSET_-number for the detected
+ * chipset, or zero on failure.
+ */
+static unsigned int speedstep_detect_chipset (void)
+{
+ speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
+ PCI_DEVICE_ID_INTEL_82801DB_12,
+ PCI_ANY_ID,
+ PCI_ANY_ID,
+ NULL);
+ if (speedstep_chipset_dev)
+ return 4; /* 4-M */
+
+ speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
+ PCI_DEVICE_ID_INTEL_82801CA_12,
+ PCI_ANY_ID,
+ PCI_ANY_ID,
+ NULL);
+ if (speedstep_chipset_dev)
+ return 3; /* 3-M */
+
+
+ speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
+ PCI_DEVICE_ID_INTEL_82801BA_10,
+ PCI_ANY_ID,
+ PCI_ANY_ID,
+ NULL);
+ if (speedstep_chipset_dev) {
+ /* speedstep.c causes lockups on Dell Inspirons 8000 and
+ * 8100 which use a pretty old revision of the 82815
+ * host brige. Abort on these systems.
+ */
+ static struct pci_dev *hostbridge;
+ u8 rev = 0;
+
+ hostbridge = pci_get_subsys(PCI_VENDOR_ID_INTEL,
+ PCI_DEVICE_ID_INTEL_82815_MC,
+ PCI_ANY_ID,
+ PCI_ANY_ID,
+ NULL);
+
+ if (!hostbridge)
+ return 2; /* 2-M */
+
+ pci_read_config_byte(hostbridge, PCI_REVISION_ID, &rev);
+ if (rev < 5) {
+ dprintk("hostbridge does not support speedstep\n");
+ speedstep_chipset_dev = NULL;
+ pci_dev_put(hostbridge);
+ return 0;
+ }
+
+ pci_dev_put(hostbridge);
+ return 2; /* 2-M */
+ }
+
+ return 0;
+}
+
+static unsigned int _speedstep_get(cpumask_t cpus)
+{
+ unsigned int speed;
+ cpumask_t cpus_allowed;
+
+ cpus_allowed = current->cpus_allowed;
+ set_cpus_allowed(current, cpus);
+ speed = speedstep_get_processor_frequency(speedstep_processor);
+ set_cpus_allowed(current, cpus_allowed);
+ dprintk("detected %u kHz as current frequency\n", speed);
+ return speed;
+}
+
+static unsigned int speedstep_get(unsigned int cpu)
+{
+ return _speedstep_get(cpumask_of_cpu(cpu));
+}
+
+/**
+ * speedstep_target - set a new CPUFreq policy
+ * @policy: new policy
+ * @target_freq: the target frequency
+ * @relation: how that frequency relates to achieved frequency (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
+ *
+ * Sets a new CPUFreq policy.
+ */
+static int speedstep_target (struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ unsigned int newstate = 0;
+ struct cpufreq_freqs freqs;
+ cpumask_t cpus_allowed;
+ int i;
+
+ if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0], target_freq, relation, &newstate))
+ return -EINVAL;
+
+ freqs.old = _speedstep_get(policy->cpus);
+ freqs.new = speedstep_freqs[newstate].frequency;
+ freqs.cpu = policy->cpu;
+
+ dprintk("transiting from %u to %u kHz\n", freqs.old, freqs.new);
+
+ /* no transition necessary */
+ if (freqs.old == freqs.new)
+ return 0;
+
+ cpus_allowed = current->cpus_allowed;
+
+ for_each_cpu_mask(i, policy->cpus) {
+ freqs.cpu = i;
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+ }
+
+ /* switch to physical CPU where state is to be changed */
+ set_cpus_allowed(current, policy->cpus);
+
+ speedstep_set_state(newstate);
+
+ /* allow to be run on all CPUs */
+ set_cpus_allowed(current, cpus_allowed);
+
+ for_each_cpu_mask(i, policy->cpus) {
+ freqs.cpu = i;
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+ }
+
+ return 0;
+}
+
+
+/**
+ * speedstep_verify - verifies a new CPUFreq policy
+ * @policy: new policy
+ *
+ * Limit must be within speedstep_low_freq and speedstep_high_freq, with
+ * at least one border included.
+ */
+static int speedstep_verify (struct cpufreq_policy *policy)
+{
+ return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]);
+}
+
+
+static int speedstep_cpu_init(struct cpufreq_policy *policy)
+{
+ int result = 0;
+ unsigned int speed;
+ cpumask_t cpus_allowed;
+
+ /* only run on CPU to be set, or on its sibling */
+#ifdef CONFIG_SMP
+ policy->cpus = cpu_sibling_map[policy->cpu];
+#endif
+
+ cpus_allowed = current->cpus_allowed;
+ set_cpus_allowed(current, policy->cpus);
+
+ /* detect low and high frequency */
+ result = speedstep_get_freqs(speedstep_processor,
+ &speedstep_freqs[SPEEDSTEP_LOW].frequency,
+ &speedstep_freqs[SPEEDSTEP_HIGH].frequency,
+ &speedstep_set_state);
+ set_cpus_allowed(current, cpus_allowed);
+ if (result)
+ return result;
+
+ /* get current speed setting */
+ speed = _speedstep_get(policy->cpus);
+ if (!speed)
+ return -EIO;
+
+ dprintk("currently at %s speed setting - %i MHz\n",
+ (speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) ? "low" : "high",
+ (speed / 1000));
+
+ /* cpuinfo and default policy values */
+ policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+ policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+ policy->cur = speed;
+
+ result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs);
+ if (result)
+ return (result);
+
+ cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu);
+
+ return 0;
+}
+
+
+static int speedstep_cpu_exit(struct cpufreq_policy *policy)
+{
+ cpufreq_frequency_table_put_attr(policy->cpu);
+ return 0;
+}
+
+static struct freq_attr* speedstep_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
+
+static struct cpufreq_driver speedstep_driver = {
+ .name = "speedstep-ich",
+ .verify = speedstep_verify,
+ .target = speedstep_target,
+ .init = speedstep_cpu_init,
+ .exit = speedstep_cpu_exit,
+ .get = speedstep_get,
+ .owner = THIS_MODULE,
+ .attr = speedstep_attr,
+};
+
+
+/**
+ * speedstep_init - initializes the SpeedStep CPUFreq driver
+ *
+ * Initializes the SpeedStep support. Returns -ENODEV on unsupported
+ * devices, -EINVAL on problems during initiatization, and zero on
+ * success.
+ */
+static int __init speedstep_init(void)
+{
+ /* detect processor */
+ speedstep_processor = speedstep_detect_processor();
+ if (!speedstep_processor) {
+ dprintk("Intel(R) SpeedStep(TM) capable processor not found\n");
+ return -ENODEV;
+ }
+
+ /* detect chipset */
+ if (!speedstep_detect_chipset()) {
+ dprintk("Intel(R) SpeedStep(TM) for this chipset not (yet) available.\n");
+ return -ENODEV;
+ }
+
+ /* activate speedstep support */
+ if (speedstep_activate()) {
+ pci_dev_put(speedstep_chipset_dev);
+ return -EINVAL;
+ }
+
+ return cpufreq_register_driver(&speedstep_driver);
+}
+
+
+/**
+ * speedstep_exit - unregisters SpeedStep support
+ *
+ * Unregisters SpeedStep support.
+ */
+static void __exit speedstep_exit(void)
+{
+ pci_dev_put(speedstep_chipset_dev);
+ cpufreq_unregister_driver(&speedstep_driver);
+}
+
+
+MODULE_AUTHOR ("Dave Jones <davej@codemonkey.org.uk>, Dominik Brodowski <linux@brodo.de>");
+MODULE_DESCRIPTION ("Speedstep driver for Intel mobile processors on chipsets with ICH-M southbridges.");
+MODULE_LICENSE ("GPL");
+
+module_init(speedstep_init);
+module_exit(speedstep_exit);